Use of ingap for reversing diabetes

ABSTRACT

The present invention relates to a method to stimulate reversal of a diabetic state in a patient; a method to prevent autoimmune destruction of new insulin-producing cells (pancreatic beta-cells) in a patient; a method to promote survival of the newly regenerated insulin-producing cells (pancreatic beta-cells); and an in vivo method for the induction of islet cell neogenesis and new islet formation and the prevention of autoimmune destruction of said new cells.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

This invention relates to a method to stimulate reversal of a diabeticstate in a patient; a method to prevent autoimmune destruction of newinsulin-producing cells (pancreatic beta-cells) in a patient; a methodto promote survival of the newly regenerated insulin-producing cells(pancreatic beta-cells); and an in vivo method for the induction ofislet cell neogenesis and new islet formation and the prevention ofautoimmune destruction of said new cells; pharmaceutical compositionsand uses thereof.

(b) Description of Prior Art

Diabetes

Diabetes mellitus has been classified as type I, or insulin-dependentdiabetes mellitus (IDDM) and type II, or non-insulin-dependent diabetesmellitus (NIDDM). NIDDM patients have been subdivided further into (a)nonobese (possibly IDDM in evolution), (b) obese, and (c) maturity onset(in young patients). Among the population with diabetes mellitus, about20% suffer from IDDM. Diabetes develops either when a diminished insulinoutput occurs or when a diminished sensitivity to insulin cannot becompensated for by an augmented capacity for insulin secretion. Inpatients with IDDM, a decrease in insulin secretion is the principalfactor in the pathogenesis, whereas in patients with NIDDM, a decreasein insulin sensitivity is the primary factor. The mainstay of diabetestreatment, especially for type I disease, has been the administration ofexogenous insulin.

Rationale for More Physiologic Therapies

Tight glucose control appears to be the key to the prevention of thesecondary complications of diabetes. The results of the DiabetesComplications and Control Trial (DCCT), a multicenter randomized trialof 1441 patients with insulin dependent diabetes, indicated that theonset and progression of diabetic retinopathy, nephropathy, andneuropathy could be slowed by intensive insulin therapy (The DiabetesControl and Complication Trial Research Group, N. Engl. J. Med., 1993;29:977-986). Strict glucose control, however, was associated with athree-fold increase in incidence of severe hypoglycemia, includingepisodes of seizure and coma. As well, although glycosylated hemoglobinlevels decreased in the treatment group, only 5% maintained an averagelevel below 6.05% despite the enormous amount of effort and resourcesallocated to the support of patients on the intensive regime (TheDiabetes Control and Complication Trial Research Group, N. Engl. J.Med., 1993; 29:977-986). The results of the DCCT clearly indicated thatintensive control of glucose can significantly reduce (but notcompletely protect against). the long-term microvascular complicationsof diabetes mellitus.

Other Therapeutic Options

The delivery of insulin in a physiologic manner has been an elusive goalsince insulin was first purified by Banting, Best, McLeod and Collip.Even in a patient with tight glucose control, however, exogenous insulinhas not been able to achieve the glucose metabolism of an endogenousinsulin source that responds to moment-to-moment changes in glucoseconcentration and therefore protects against the development ofmicrovascular complications over the long term.

A major goal of diabetes research, therefore, has been the developmentof new forms of treatment that endeavor to reproduce more closely thenormal physiologic state. One such approach, a closed-loop insulin pumpcoupled to a glucose sensor, mimicking p-cell function in which thesecretion of insulin is closely regulated, has not yet been successful.Only total endocrine replacement therapy in the form of a transplant hasproven effective in the treatment of diabetes mellitus. Althoughtransplants of insulin-producing tissue are a logical advance oversubcutaneous insulin injections, it is still far from clear whether therisks of the intervention and of the associated long-termimmunosuppressive treatment are lower those in diabetic patients underconventional treatment.

Despite the early evidence of the potential benefits of vascularizedpancreas transplantation: it remains a complex surgical intervention,requiring the long-term administration of chronic immunosuppression withits attendant side effects. Moreover, almost 50% of successfullytransplanted patients exhibit impaired tolerance curves (Wright F H etal., Arch. Surg., 1989;124:796-799; Landgraft R et al., Diabetologia1991; 34 (suppl 1):S61; Morel P et al., Transplantation 1991;51:990-1000), raising questions about their protection against thelong-term complications of chronic hyperglycemia.

The major complications of whole pancreas transplantation, as well asthe requirement for long term immunosuppression, has limited its widerapplication and provided impetus for the development of islettransplantation. Theoretically, the transplantation of islets alone,while enabling tight glycemic control, has several potential advantagesover whole pancreas transplantation. These include the following: (i)minimal surgical morbidity, with the infusion of islets directly intothe liver via the portal vein; (ii) the possibility of simplere-transplantation for graft failures; (iii) the exclusion ofcomplications associated with the exocrine pancreas; (iv) thepossibility that islets are less immunogenic, eliminating the need forimmunosuppression and enabling early transplantation into non-uremicdiabetics; (v) the possibility of modifying islets in vitro prior totransplantation to reduce their immunogenicity; (vi) the ability toencapsulate islets in artificial membranes to isolate them from the hostimmune system; and (vii) the related possibility of usingxenotransplantation of islets immunoisolated as part of a biohybridsystem. Moreover, they permit the banking of the endocrine cryopreservedtissue and a careful and standardized quality control program before theimplantation.

The Problem of Islet Transplantation

Adequate numbers of isogenetic islets transplanted into a reliableimplantation site can only reverse the metabolic abnormalities indiabetic recipients in the short term. In those that were normoglycemicpost-transplant, hyperglycemia recurred within 3-12 mo. (Orloff M, et.al., Transplantation 1988; 45:307). The return of the diabetic statethat occurs with time has been attributed either to the ectopic locationof the islets, to a disruption of the enteroinsular axis, or to thetransplantation of an inadequate islet cell mass (Bretzel R G, et al.In: Bretzel R G, (ed) Diabetes mellitus (Berlin: Springer, 1990) p.229).

Studies of the long term natural history of the islet transplant, thatexamine parameters other than graft function, are few in number. Onlyone report was found in which an attempt was specifically made to studygraft morphology (Alejandro R,. et. al., J Clin Invest 1986; 78: 1339).In that study, purified islets were transplanted into the canine livervia the portal vein. During prolonged follow-up, delayed failures ofgraft function occurred. Unfortunately, the graft was only examined atthe end of the study, and not over time as function declined. Delayedgraft failures have also been confirmed by other investigators for dogs(Warnock G L et. al., Can. J. Surg., 1988; 31: 421 and primates (SuttonR, et. al., Transplant Proc., 1987; 19: 3525). Most failures arepresumed to be the result of rejection despite appropriateimmunosuppression.

Because of these failures, there is currently much enthusiasm for theimmunoisolation of islets, which could eliminate the need forimmunosuppression. The reasons are compelling. Immunosuppression isharmful to the recipient, and may impair islet function and possiblycell survival (Metrakos P, et al., J. Surg. Res., 1993; 54: 375).Unfortunately, micro-encapsulated islets injected into the peritonealcavity of the dog fail within 6 months (Soon-Shiong P, et. al.,Transplantation 1992; 54: 769), and islets placed into a vascularizedbiohybrid pancreas also fail, but at about one year. In each instance,however, histological evaluation of the graft has indicated asubstantial loss of islet mass in these devices (Lanza R P, et. al.,Diabetes 1992; 41: 1503). No reasons have been advanced for thesechanges. Therefore maintenance of an effective islet cell masspost-transplantation remains a significant problem.

In addition to this unresolved issue, is the ongoing problem of the lackof source tissue for transplantation. The number of human donors isinsufficient to keep up with the potential number of recipients.Moreover, given the current state of the art of islet isolation, thenumber of islets that can be isolated from one. pancreas is far from thenumber required to effectively reverse hyperglycemia in a humanrecipient.

In response, three competing technologies have been proposed and areunder development. First, islet cryopreservation and islet banking. Thetechniques involved, though; are expensive and cumbersome, and do noteasily lend themselves to widespread adoption. In addition, islet cellmass is also lost during the freeze-thaw cycle. Therefore this is a poorlong-term solution to the problem of insufficient islet cell mass.Second, is the development of islet xenotransplantation. This idea hasbeen coupled to islet encapsulation technology to produce a biohybridimplant that does not, at least in theory, require immunosuppression.There remain many problems to solve with this approach, not least ofwhich, is that the problem of the maintenance of islet cell mass in thepost-transplant still remains. Third, is the resort to human fetaltissue, which should have a great capacity to be expanded ex vivo andthen transplanted. However, in addition to the problems of limitedtissue availability, immunogenicity, there are complex ethical issuessurrounding the use of such a tissue source that will not soon beresolved. However, there is an alternative that offers similarpossibilities for near unlimited cell mass expansion.

An entirely novel approach, proposed by Rosenberg in 1995 (Rosenberg Let al., Cell Transplantation, 1995; 4:371-384), was the development oftechnology to control and modulate islet cell neogenesis and new isletformation, both in vitro and in vivo. The concept assumed that (a) theinduction of islet cell differentiation was in fact controllable; (b)implied the persistence of a stem cell-like cell in the adult pancreas;and (c) that the signal(s) that would drive the whole process could beidentified and manipulated.

In a series of in vivo studies, Rosenberg and co-workers establishedthat these concepts were valid in principle, in the in vivo setting(Rosenberg L et al., Diabetes, 1988; 37:334-341; Rosenberg L et al.,Diabetologia, 1996; 39:256-262), and that diabetes could be reversed.

The well known teachings of in vitro islet cell expansion from anon-fetal tissue source comes from Peck and co-workers (Corneliu J G etal., Horm. Metab. Res., 1997; 29:271-277), who describe isolation of apluripotent stem cell from the-adult mouse pancreas that can be directedtoward an insulin-producing cell. These findings have not been widelyaccepted. First, the result has not proven to be reproducible. Second,the so-called pluripotential cells have never been adequatelycharacterized with respect to phenotype. And third, the cells havecertainly not been shown to be pluripotent.

More recently two other competing technologies have been proposed theuse of engineered pancreatic p-cell lines (Efrat S, Advanced DrugDelivery Reviews, 1998; 33:45-52), and the use of pluripotent embryonalstem cells (Shambloft M J et al., Proc. Natl. Acad. Sci. USA, 1998;95:13726-13731). The former option while attractive, is associated withsignificant problems. Not only must the engineered cell be able toproduce insulin, but it must respond in a physiologic manner to theprevailing level of glucose- and the glucose sensing mechanism is farfrom being understood well enough to engineer it into a cell. Manyproposed cell lines are also transformed lines, and therefore have aneoplastic potential. With respect to the latter option, having anembryonal stem cell in hand is appealing because of the theoreticalpossibility of being able to induce differentiation in any direction,including toward the pancreatic p-cell. However, the signals necessaryto achieve this milestone remain unknown.

Islet neogenesis associated protein (INGAP) is a mediator of in vivoislet cell neogenesis from. pancreatic duct epithelial cells in severalspecies.

It would be highly desirable to be provided with a method for the invivo induction of re-growth of new insulin-producing cells leading tothe formation of mature islets of Langerhans using INGAP peptide (thebiologically active portion of the INGAP molecule), as a means ofrevering an established diabetic state.

Moreover, if such a diabetic was caused by pre-existing or ongoingautoimmunity, it would also be highly desirable to be provided with amethod for the mitigation of such autoimmunity so that theaforementioned newly re-grown cells will not be subjected to ongoing orrenewed destruction.

SUMMARY OF THE INVENTION

One aim of the invention is to provide a method to stimulate reversal ofa diabetic state in a patient.

Another aim of the invention is to provide a method to preventautoimmune destruction of new insulin-producing cells (pancreaticbeta-cells) in a patient.

Another aim of the invention is to provide a method to promote survivalof the newly regenerated insulin-producing cells (pancreaticbeta-cells).

Another aim of the invention is to provide an in vivo method for theinduction of islet cell neogenesis and new islet formation and theprevention of autoimmune destruction of the new cells.

In accordance with the present invention there is provided a method tostimulate reversal of a diabetic state in a patient, which comprises invivo inducing re-growth of new insulin-producing cells by administeringa therapeutically effective amount of a pro-neogenesis factor to saidpatient, wherein formation of mature islets of Langerhans is indicativeof a stimulated reversal of a diabetic state.

In accordance with the present invention there is provided a method toprevent autoimmune destruction of new insulin-producing cells(pancreatic beta-cells) in a patient, which comprises administering tosaid patient a therapeutically effective amount of at least oneimmunosuppressive agent in combination with an INGAP peptide.

In accordance with the present invention there is provided an in vivomethod for the induction of islet cell neogenesis and new isletformation and the prevention of autoimmune destruction of said newcells, which comprises the steps of:

-   -   a) administering INGAP peptide to said patient in an amount        sufficient to stimulate transformation of putative islet cell        stem/progenitor cells in adult pancreas into islet        hormone-producing cells under normal endogenous homeostatic        control mechanisms, whereby cells expand in number and develop a        mature glucose-sensing mechanism in a regulated manner;    -   b) concurrently administering to said patient at least one        immunosuppressive agent in an amount sufficient to protect said        islet cells from immune destruction; and    -   c) concurrently administering a pro-survival factor to said        patient during islet cell neogenesis and new islet formation.

In accordance with the present invention there is provided an in vivomethod for the induction of islet cell neogenesis and new isletformation and the prevention of autoimmune destruction of said newcells, which comprises the steps of:

-   -   a) administering INGAP peptide to said patient in an amount        sufficient to stimulate transformation of putative islet cell        stem/progenitor cells in adult pancreas into islet        hormone-producing cells under normal endogenous homeostatic        control mechanisms, whereby cells expand in number and develop a        mature glucose-sensing mechanism in a regulated manner;    -   b) concurrently administering a pro-survival factor to said        patient during islet cell neogenesis and new islet formation.

In accordance with the present invention there is provided apharmaceutical composition for the preparation of a medicament tostimulate reversal of a diabetic state in a patient by in vivo inducingre-growth of new insulin-producing cells, which comprises atherapeutically effective amount of a pro-neogenesis factor inassociation with a pharmaceutically acceptable carrier.

In accordance with the present invention there is provided apharmaceutical composition for the preparation of a medicament toprevent autoimmune destruction of new insulin-producing cells in apatient, which comprises a therapeutically effective amount of at leastone immunosuppressive agent and an INGAP peptide factor in associationwith a pharmaceutically acceptable carrier.

In accordance with the present invention there is provided apharmaceutical composition for the preparation of a medicament topromote survival of the newly regenerated insulin-producing cells, whichcomprises a therapeutically effective amount of a pro-neogenesis factorin association with a pharmaceutically acceptable carrier.

In accordance with the present invention there is provided apharmaceutical composition for the preparation of a medicament for theinduction of islet cell neogenesis and new islet formation and theprevention of autoimmune destruction of said new cells, which comprisesan INGAP peptide in an amount sufficient to stimulate transformation ofputative islet cell stem/progenitor cells in adult pancreas into islethormone-producing cells under normal endogenous homeostatic controlmechanisms; at least one immunosuppressive agent in an amount sufficientto protect said islet cells from immune destruction; and a pro-survivalfactor in association with a pharmaceutically acceptable carrier.

In accordance with the present invention there is provided apharmaceutical composition for the preparation of a medicament for theinduction of islet cell neogenesis and new islet formation and theprevention of autoimmune destruction of said new cells, which comprisesan INGAP peptide in an amount sufficient to stimulate transformation ofputative islet cell stem/progenitor cells in adult pancreas into islethormone-producing cells under normal endogenous homeostatic controlmechanisms; and a pro-survival factor in association with apharmaceutically acceptable carrier.

The immunosuppressive agent includes, without limitation, sirolimus,tacrolimus, or a combination thereof.

The term “pro-neogenesis factor” is intended to mean any compoundscapable of islet regeneration including, without limitation, growthfactors, GLP-1, exendin-4, and an INGAP peptide.

The preferred growth factors are selected from the group consisting ofinsulin, IGF-I, IGF-II, EGF, Gastrin and NGF.

The term “pro-survival factor” is, intended to mean a factor including,without limitation, insulin, IGF-I, IGF-II, EGF and NGF.

The term “insulin-producing cells” is intended to mean pancreaticbeta-cells.

The term “INGAP peptide” is intended to mean the fragment of nativeIslet Neogenesis Associated Protein (INGAP) protein which contains thebiological activity of the full length molecule, including but notlimited to, a biologically active fragment of: (SEQ ID NO:1) Met Leu ProMet Thr Leu Cys Arg Met Ser Trp Met Leu Leu Ser Cys  1               5                  10                  15 Leu Met PheLeu Ser Trp Val Glu Gly Glu Glu Ser Gln Lys Lys Leu             20                 25                  30 Pro Ser Ser ArgIle Thr Cys Pro Gln Gly Ser Val Ala Tyr Gly Ser         35                  40                 45 Tyr Cys Tyr Ser LeuIle Leu Ile Pro Gln Thr Trp Ser Asn Ala Glu     50                  55                  60 Leu Ser Cys Gln Met HisPhe Ser Gly His Leu Ala Phe Leu Leu Ser 65                 70                  75                  80 Thr GlyGlu Ile Thr Phe Val Ser Ser Leu Val Lys Asn Ser Leu Thr                 85                  90                  95 Ala Tyr GlnTyr Ile Trp Ile Gly Leu His Asp Pro Ser His Gly Thr            100                 105                 110 Leu Pro Asn GlySer Gly Trp Lys Trp Ser Ser Ser Asn Val Leu Thr        115                 120                 125 Phe Tyr Asn Trp GluArg Asn Pro Ser Ile Ala Ala Asp Arg Gly Tyr    130                 135                 140 Cys Ala Val Leu Ser GlnLys Ser Gly Phe Gln Lys Trp Arq Asp Phe145                 150                 155                 160 Asn CysGlu Asn Glu Leu Pro Tyr Ile Cys Lys Phe Lys Val,                165                 170a fragment of 15 amino acids of the sequence SEQ ID NO: 1, moreprecisely, such an INGAP peptide is of the following amino acidsequence: Gly Leu His Asp Pro Ser His Gly Thr Leu Pro Asn Gly Ser Gly(SEQ ID NO:2).

The term “islets of Langerhans” is intended to mean islet cells andassociated cells, such as duct cells, of any origin, such as human,porcine, canine and murine, among others.

The term “neogenesis” is intended to mean the regeneration or de novogrowth of cells.

Except as otherwise expressly defined herein, the abbreviations usedherein for designating the amino acids and the protective groups arebased on recommendations of the IUPAC-IUB Commission on BiochemicalNomenclature (Biochemistry, 1972,11:1726-1732).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the increase in pancreatic insulin content and thereduction in the prevailing level of blood glucose resulting from theconcurrent administration of INGAP peptide and sirolimus/tacrolimus andinsulin in NOD mice.

FIG. 2 illustrates the survival of NOD mice treated with a combinationof INGAP peptide, sirolimus/tacrolimus and insulin versus animalstreated with sirolimus/tacrolimus alone or drug vehicle alone.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, there is provided a method forthe induction of in vivo islet cell neogenesis and new islet formationfrom cells derived from islet cell stem/progenitor cells in the adultpancreas, associated with the self-regulated expansion of such cells andthe development of a mature glucose-sensing mechanism, leading to thereversal of an established diabetic state.

In accordance with one embodiment of the present invention, thetechnology is based on the understanding of autoimmune diabetes being adisease state characterized by a loss of an insulin-producing cell massas a result of a pre-existing or ongoing autoimmune destruction of suchcells, incorporating the following components that are necessary andsufficient for the successful reversal of a diabetic state by theinduction of islet cell neogenesis and new islet formation:

-   -   1. a stimulus for the induction of islet cell neogenesis and new        islet formation from pre-existing pancreatic stem/progenitor        cells, provided by, but not limited to INGAP peptide;    -   2. provision of an immune tolerant environment to prevent        ongoing or recurrent destruction of the newly regenerated cells,        provided by, but not limited to, a combination of        sirolimus/tacrolimus;    -   3. a pro-survival and anti-apoptosis factor, including but not        limited to insulin.

The use of a pro-neogenesis factor is a critical part of the treatment,because without it, there is no stimulus to induce the transformation ofputative stem/progenitor cells to new hormone-producing islet cells.Alternatively, there may be such an endogenous stimulus but it may beineffectual in terms of overcoming a much more effective ongoing celldestruction process. Hence it is the balance of neogenesis versusdestruction that may be important.

Autoimmune diabetes, by definition, occurs through the autoimmunedestruction of insulin-producing pancreatic beta-cells. In order tomitigate the ongoing or renewed destruction of such cells after theinduction of islet cell neogenesis, the local immune environment must bealtered to remove or diminish this autoimmune insult. Thusimmunosuppressive agents, that include, but are not limited to acombination of sirolimus/tacrolimus, are required.

Newly created beta-cells are known to be quite sensitive pro-deathsignals including, but not limited to high levels of circulatingglucose. Thus pro-survival factors and in particular factors that canmitigate high levels of circulating glucose including, but not limitedto insulin, are important to support and sustain cell survival.

Evidence for the induction of islet cell noegenesis and new isletformation leading to the reversal of diabetes includes: (1) an increasein the expression of the transcription factor Pdx-1 in putative isletcell progenitor cells; (2) and increase in pancreatic insulin content;(3) an increase in beta-cell mass; (5) a decrease in the prevailinglevel of blood glucose; (6) an increase in survival.

While the invention has been described in connection with specificembodiments thereof, it will be understood that it is capable of furthermodifications and this application is intended to cover any variations,uses, or adaptations of the invention following, in general, theprinciples of the invention and including such departures from thepresent disclosure as come within known or customary practice within theart to which the invention pertains and as may be applied to theessential features hereinbefore set forth, and as follows in the scopeof the appended claims.

1. A method to stimulate reversal of a diabetic state in a patient,which comprises in vivo inducing re-growth of new insulin-producingcells by administering a therapeutically effective amount of apro-neogenesis factor to said patient, wherein formation of matureislets of Langerhans is indicative of a stimulated reversal of adiabetic state.
 2. The method of claim 1, wherein said pro-neogenesisfactor is selected from the group consisting of growth factors, GLP-1,exendin-4, and an INGAP peptide.
 3. The method of claim 2, wherein saidgrowth factor is selected from the group consisting of insulin, IGF-I,IGF-II, EGF, Gastrin and NGF.
 4. The method of claim 1, wherein saidinsulin-producing cells are pancreatic beta-cells.
 5. A method toprevent autoimmune destruction of new insulin-producing cells(pancreatic beta-cells) in a patient, which comprises administering tosaid patient a therapeutically effective amount of at least oneimmunosuppressive agent in combination with an INGAP peptide.
 6. Themethod of claim 5, wherein said immunosuppressive agent is selected fromthe group consisting of sirolimus, tacrolimus, and a combinationthereof.
 7. A method to promote survival of the newly regeneratedinsulin-producing cells, which comprises administering a pro-neogenesisfactor in a therapeutically effective amount to a patient.
 8. The methodof claim 7, wherein said pro-neogenesis factor is selected from thegroup consisting of growth factors, GLP-1, exendin-4, and an INGAPpeptide.
 9. The method of claim 8, wherein said growth factor isselected from the group consisting of insulin, IGF-I, IGF-II, EGF,Gastrin and NGF.
 10. The method of claim 8, wherein saidinsulin-producing cells are pancreatic beta-cells.
 11. An in vivo methodfor the induction of islet cell neogenesis and new islet formation andthe prevention of autoimmune destruction of said new cells, whichcomprises the steps of: a) administering INGAP peptide to said patientin an amount sufficient to stimulate transformation of putative isletcell stem/progenitor cells in adult pancreas into islethormone-producing cells under normal endogenous homeostatic controlmechanisms, whereby cells expand in number and develop a matureglucose-sensing mechanism in a regulated manner; b) concurrentlyadministering to said patient at least one immunosuppressive agent in anamount sufficient to protect said islet cells from immune destruction;and c) concurrently administering a pro-survival factor to said patientduring islet cell neogenesis and new islet formation.
 12. The method ofclaim 11, wherein said islet hormone-producing cells are pancreaticbeta-cells.
 13. The method of claim 12, wherein said immunosuppressiveagent is selected from the group consisting of sirolimus, tacrolimus,and a combination thereof.
 14. The method of claim 11, wherein saidpro-survival factor is selected from the group consisting of insulin,IGF-I, IGF-II, EGF and NGF.
 15. An in vivo method for the induction ofislet cell neogenesis and new islet formation and the prevention ofautoimmune destruction of said new cells, which comprises the steps of:a) administering INGAP peptide to said patient in an amount sufficientto stimulate transformation of putative islet cell stem/progenitor cellsin adult pancreas into islet hormone-producing cells under normalendogenous homeostatic control mechanisms, whereby cells expand innumber and develop a mature glucose-sensing mechanism in a regulatedmanner; b) concurrently administering a pro-survival factor to saidpatient during islet cell neogenesis and new islet formation.
 16. Themethod of claim 15, wherein said islet hormone-producing cells arepancreatic beta-cells.
 17. The method of claim 15, wherein saidpro-survival factor is selected from the group consisting of insulin,IGF-I and IGF-II.
 18. A pharmaceutical composition for the preparationof a medicament to stimulate reversal of a diabetic state in a patientby in vivo inducing re-growth of new insulin-producing cells, whichcomprises a therapeutically effective amount of a pro-neogenesis factorin association with a pharmaceutically acceptable carrier.
 19. Thepharmaceutical composition of claim 18, wherein said pro-neogenesisfactor is selected from the group consisting of growth factors, GLP-1,exendin-4, and an INGAP peptide.
 20. The pharmaceutical composition ofclaim 18, wherein said growth factor is selected from the groupconsisting of insulin, IGF-I, IGF-II, EGF, Gastrin and NGF.
 21. Apharmaceutical composition for the preparation of a medicament toprevent autoimmune destruction of new insulin-producing cells in apatient, which comprises a therapeutically effective amount of at leastone immunosuppressive agent and an INGAP peptide factor in associationwith a pharmaceutically acceptable carrier.
 22. The pharmaceuticalcomposition of claim 21, wherein said immunosuppressive agent isselected from the group consisting of sirolimus, tacrolimus, and acombination thereof.
 23. A pharmaceutical composition for thepreparation of a medicament to promote survival of the newly regeneratedinsulin-producing cells, which comprises a therapeutically effectiveamount of a pro-neogenesis factor in association with a pharmaceuticallyacceptable carrier.
 24. The pharmaceutical composition of claim 23,wherein said pro-neogenesis factor is selected from the group consistingof growth factors, GLP-1, exendin-4, and an INGAP peptide.
 25. Thepharmaceutical composition of claim 24, wherein said growth factor isselected from the group consisting of insulin, IGF-I, IGF-II, EGF,Gastrin and NGF.
 26. The pharmaceutical composition of claim 23, whereinsaid insulin-producing cells are pancreatic beta-cells.
 27. Apharmaceutical composition for the preparation of a medicament for theinduction of islet cell neogenesis and new islet formation and theprevention of autoimmune destruction of said new cells, which comprisesan INGAP peptide in an amount sufficient to stimulate transformation ofputative islet cell stem/progenitor cells in adult pancreas into islethormone-producing cells under normal endogenous homeostatic controlmechanisms; at least one immunosuppressive agent in an amount sufficientto protect said islet cells from immune destruction; and a pro-survivalfactor in association with a pharmaceutically acceptable carrier. 28.The pharmaceutical composition of claim 27, wherein said islethormone-producing cells are pancreatic beta-cells.
 29. Thepharmaceutical composition of claim 27, wherein said immunosuppressiveagent is selected from the group consisting of sirolimus, tacrolimus,and a combination thereof.
 30. The pharmaceutical composition of claim29, wherein said pro-survival factor is selected from the groupconsisting of insulin, IGF-I, IGF-II, EGF and NGF.
 31. A pharmaceuticalcomposition for the preparation of a medicament for the induction ofislet cell neogenesis and new islet formation and the prevention ofautoimmune destruction of said new cells, which comprises an INGAPpeptide in an amount sufficient to stimulate transformation of putativeislet cell stem/progenitor cells in adult pancreas into islethormone-producing cells under normal endogenous homeostatic controlmechanisms; and a pro-survival factor in association with apharmaceutically acceptable carrier.
 32. The pharmaceutical compositionof claim 31, wherein said islet hormone-producing cells are pancreaticbeta-cells.
 33. The pharmaceutical composition of claim 31, wherein saidpro-survival factor is selected from the group consisting of insulin,IGF-I, IGF-II, EGF, and NGF. 34-49. (canceled)